1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Y

B

Z

A

GND2

DW PACKAGE

GND2

NC

R

RE

D

D1

DE

GND1

D2

V

CC1

V

CC2

DE

7

D

8

R

5

6

RE

Y

Z

B

A

14

11

12

13

D1

2

OSC

1

D2

ISO35T

www.ti.com

SLLSE26C

– NOVEMBER 2010 – REVISED AUGUST 2011

Isolated 3.3V RS-485 Transceiver With Integrated Transformer Driver

Check for Samples: ISO35T

1

FEATURES

•

•

Bus-Pin ESD Protection

– 16 kV HBM Between Bus-Pins and GND2

– 6 kV HBM Between Bus-Pins and GND1

•

1/8 Unit Load

– Up to 256 Nodes on a Bus

•

Designed for RS-485 and RS-422 Applications

•

Signaling Rates up to 1 Mbps

•

Thermal Shutdown Protection

FUNCTION DIAGRAM

•

Typical Efficiency

- see SLUU470

•

Low Driver Bus Capacitance 16 pF (Typ)

•

50 kV/

µs Typical Transient Immunity

•

UL 1577, IEC 60747-5-2 (VDE 0884, Rev. 2)

Approvals Pending

•

Fail-safe Receiver for Bus Open, Short, Idle

•

Logic Inputs are 5-V Tolerant

APPLICATIONS

•

Isolated RS-485/RS-422 Interfaces

•

Factory Automation

•

Motor/Motion Control

•

HVAC and Building Automation Networks

•

Networked Security Stations

DESCRIPTION

The ISO35T is an isolated differential line transceiver with integrated oscillator outputs that provide the primary

voltage for an isolation transformer. The device is a full-duplex differential line transceiver for RS-485 and

RS-422 applications that can easily be configured for half-duplex operation by connecting pin 11 to pin 14, and

pin 12 to pin 13.

These devices are ideal for long transmission lines since the ground loop is broken to allow for a much larger

isolation per VDE for 60s between the bus-line transceiver and the logic-level interface.

Any cabled I/O can be subjected to electrical noise transients from various sources. These noise transients can

cause damage to the transceiver and/or near-by sensitive circuitry if they are of sufficient magnitude and

duration. The ISO35T can significantly reduce the risk of data corruption and damage to expensive control

circuits.

The ISO35T is specified for use from

–40°C to 85°C.

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Copyright

© 2010–2011, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.